Process and apparatus for reducing middlings



H. M. WHITNEY.

PROCESS AND APPARATUS FOR REDUCING MIDDLINGS.

APPLICATION FILED MAR. 22. m9.

1,357501 5. Patented 00a 26,1920.

4 SHEETSSHEET 1.

I 7 La ,4; {g

H. M. WHITNEY.

PROCESS AND APPARATUS FOR REDUQING MIDDLINGS. APPLICATION FILED MAR. 22. 1919.

1,357,015. r Patented Oct. 26,1920.

4 SHEETS-SHEET 2.

402765565 A Jive/27%.

W I 21 a Mam/7 H. M. WHITNEY,

PROCESS AND APPARATUS'FOR REDUCING MIDDLINGS.

APPLICATION FILED MAR. 22. 1919.

Patented Oct. 26, 1920.

' .4 SHEETS-SHEET 3.

fizz/677 257 H. M. WHITNEY.-

PROCtSSAND APPARATUS FOR REDUCINGMIDDLINGS.

APPLICATION FILED MAR. 22, 1919.

1,357,015; I Patented Oct. 26; 1920.

4 SHEETS-SHEET 4-.

UNITED STATES OFFICE; J

HUGH ivr. WHITNEY, OF WEBSTER GROVES, ivirssounr, ASSIGNOR TO WHITNEY MILLING MACHINE 00., or sT. LOUIS, MISSOURI, A CORPORATION or ms;

SOURI.

' rnocnss AND APPARATUS FOR REDUCING MIDDLINGS.

Specification of Letters'Patent. Pat-g t d O t 26 1920 Application filed March 22,1919. Serial No. 284366.

Y '0 all whom it may concern: 1

Be it known that I, HUGH M. WHITNEY, a citizen of the United States, residing at obster Groves, in the county of St. Louis and State of Missouri, have invented certain new and usefullmprovements in Processes and Apparatus for Reducing Middlings, of

which the following is a specification.

The present invention relates to the treatment of middlings in reducing its contained flour, and has for itsobject to effect the necessary reduction of middlings greater efficiency, with much less expenditure of energy, and with greatly improved product than has been attainable with methods and apparatus heretofore used for this purpose.

The present invention proceeds upon the discovery that if middlings from any suitable form of breaking mechanism (preferably after the usual scalping) are passed to a pair of reducing elements, which have their surfaces dressed with corrugations extending in the direction of feed, and if relative axial movement be developed between these reducing elements simultaneously with the feed of the material between them, the flour content of the middlings will be reduced and separated without reduction of the germy middlings or the woody fiber middlings, so that the flour is ofvery superior quality, and the germy and woody fiber portion of the middlings will not be reduced orfdisintegrated, but will be fiattened out in a manner to greatly facilitate its separation from the flour.

The middlings are best delivered to the reducing elements in a sheet. For convenience in developing an effective feed, one of the reducing elements is preferably in the form of a revolving roll, while the other is in the form of a concave. The concave, being of lighter weight, affords the better medium through which to develop relative reciprocation that produces the rubbing action be tween the elements, and it is therefore-provided with means for imparting reciprocae tion in a line intersecting the line of feed.

It has heretofore beenoproposed'to use rolls and concaves with their surfaces dressed with corrugations extending in the direction'of feed for breaking the grain to produce the middlings. Such a method of breaking and production of middlings is with 1 very superior in its effect, and is preferably and the same is productive of very superior results in the particulars already mentioned. An important feature of the present invention residesin the character of the corrugations employed and their relation to the material to beoperated upon, and this character is identified not only by the number of corrugations but, also by their pitch, or the angle of their sides to the surface of the reducing member, and therefore the angle of incidence which they present to the material upon which they areoperating, and even by the depth, and, to some extent, the shape of the bottom spacesbetween them. Not all of these features are indispensable to a measurable realization of the good results obtainedby the invention; they are merely recited by way of indicating the best conditions by which to realize the advantages of the invention in the fullest measure. That is to say i The number of corrugations to the inch would be governed largely by the size of the middlings to be operated upon, the finer middlings responding best to the finer corrugations, and vice versa. But it is not necessary that any exact relationship be established;-on the contrary, where, as is usually the case, the middlings vary in, size, the

coarseness of corrugations may be selected to correspond to the average size of the middlings to be treated. The pitch of the corrugations or the angle which their sides present to the material upon which the corrugations operate in the relative axial, movement is a very important feature of the application of the principle of corrugated elements to the reduction of iniddlings. If the pitch is too abrupt or at too great an angle to the surface of the member, the germy and Woody sirable.

fibrous middlings will be cut or disintegrated in a manner to discolor or reduce the quality of the flour, which is very unde- Whereas, if a pitch be selected which presents the sides of the corrugations at a much less angle to the surface of the member, the coacting elements will act to flatten out the germy and woody fibrous middlings without disintegrating them, and leave this part of the middlings in particularly advantageous condition to be separated from the flour by the ordinary screen. methods, and thereby rendering the costly element of middlings purifiers wholly unnecessary. 1

The depth of the grooves becomes important mainly in adapting the dress to the size of the middlings. The shape of the bottom of the grooves is important mainly to facilitate keeping the grooves clean and avoiding the packing of the flour into the bottoms of the grooves and the elimination of the corrugations, the bottoms of the grooves, for this reason, being preferably made arcuate as distinguished from angu--' lar. The outer edges or crests of the corrugations should be angular, and it is very im' portant that these crests all terminate in the same geometrical cylindrical surface.

It is important to set and maintain the two coacting elements with their grooves in parallel planes. It is relatively unimportant that the two elements should be set close together in their'oaeration; indeed, an important feature of the present invention resides in the fact that much greater spacing of the reducing elements, and consequently much greater stream of material can be passed through in a given time than with reducing elements as heretofore known. It is important that the corrugations be in planes perpendicular to the axes of the reducing elements, and that the corrugations of one element remain at all times parallel with those of the other, but it is not important that exactly the same number of corrugations be used upon the two elements; on the contrary, there is a distinct advantage in the matter of reducing shock or vibration to the machinery to have the numbers of corrugations in the coacting elements sufliciently difierent to avoid the passing of any considerable number of the corrugations simultaneously in the relative axial movement which is developed between the members.

An illustrative apparatus that may be used for practising the process forming one part of the present invention, and which apparatus embodies some novel features of construction, is illustrated in the accompanying drawings, in which- Figure 1 is an end elevation of such a middlings reduction machine, parts being shown in section to elucidate the adjustment to be developed in the rolls, as well as the means employed for developing relative rcciprocation between the reducing elements.

F 2 is a plan view partly in s ction to disclose means for driving the concaves in the development of the relative axial reciprocation.

Fig. 3 is a detail View showing the saddle, the sliding bearings in which it reciprocates, and the concave mounted therein.

Fig. 4 is a detail View of the means for developing reciprocation in the saddle of the concave. I

Fig. 5 is a detail view of one of the bearings for a roll with its eccentric adjustment, through means of which the corrugations of a roll are kept parallel with those of the concave.

Fig. 6 is a detail view of the means for adjusting the grinding distance. of the rolls, together with the means for throwing the rolls away from their concaves when not grinding.

Fig. 7 is a sectional detail view on a magnified scale illustrating the corrugations that may be employed upon a roll and its coacting concave.

Fig. 8 is a schematic view illustrating the combined break and middlings reduction process.

Figs. 9 and 10 show schematically modt fied arrangements of coacting reducing elements.

Figs. 11 and 12 are two fragmentary views on a magnified scale showing the form of corrugations with which thecoacting surfaces of the reducing members are provided.

Referring to Fig. 8, which represents schematically a complete process embodying the various features of the present invention, A A A and A" represent a series of breaks for reducing the wheat into middlings, and of which there may be more or less than the number shown. B to B represent scalpers adapted to treat the material from each of the breaks to separate the middlings from the bran, the bran from each scalper except the last being preferably passed to a succeeding breaker, and the tailings from the last being disposed of in the usual way, as, for instance, by sending to feed.

The middlings from the several scalpers, according to this process, are preferably sent direct to the middlings reduction machine.

The breaks A etc., may be of any approved construction, but they are preferably of the known type in which cooperating concaves and rolls are employed having their surfaces dressed with corrugations in planes perpendicular to the axes of the elements, and with means for developing, preferably by a reciprocating motion of the concave, a relative axial movement between the elements. The advantage of breaking grain by. this type of break has long been recommended, but it-may be applied with peculiar advantage to the particular .construction of middlings reduction machine forming part of this invention, or as a .step preliminary to the method of reducing the middlings herein described. T his advantage arises mainly from the fact that when grain is broken by the jcircum'ferentially corrugated roll and concave, it makes larger and more uniform middlings, and this character of middlings responds with special advantage to the process of my present invention,

" will be preferably made with two pairsof reduction units, each with a known type of automatic feed 1, which delivers the mid dlings automatically to a retaining hopper 2 overlying the high point of the roll 3 and extending somewhat backward from the high point, so that the middlings will be retained in said hopper until they can arrange themselves in the grooved surface of the roll, when they will feed forward and downward to the space between the roll and the concave 4, there to be acted upon in accord ance with the present invention. In closing the end of the retaining hopper 2, a leather facing strip 2 is employed which conforms accurately to the surface of the roll, and has a tongue 2 extending forward and downward to close the end of the space between the roll 3 and the concave 4:.

The concaves 4 are carried by saddles 5 which are mounted to reciprocate in the bearings 6 on the frame of the machine, and are provided with bearing ends '7 that receive the connecting rods 8 extending from one end of each concave longitudinally through the machine to the other end thereof, where they are connected by bearing straps 9 to the eccentric shaft 10. This eccentric shaft receives constant rotation dur-- ing the operation of the machine and imparts reciprocating movement to the concaves 4. The eccentrics 1O on the shaft 10 concaves. trated, this is accomplished by a pillow block movement will have some efi'ect upon the capacity of the machine; I prefer to impart a throw of from one-half to one inch in the reduction ofxmiddlings, and the rate of reciprocation will be from 250 to 100- per minute, according to the character of'the material operated upon. In mounting the concaves 1 1nthe saddles 5 their meeting faces'are not constructed upon an arc, as

has sometimes been proposed, but, instead,

these meeting faces are cast or otherwise formed with chipping-strips integral therewith, and which maybe readily planed off on both faces, bringing the parts to a proper fit. The abutting faces thus developed upon the two parts are in flat planes, and thuseasily produced upon readily available machinery. Moreover, they still leave the faces of the saddle in proper form to embrace the concave and thussecurely lock the two parts together.

An important feature of my invention resides in the fact that the spacing of the roll 3 and concave 4 in the application of the corrugated reducing elements to a middlings reduction machine is not so close as to cut the granular material of the middlings between the passing ridges, but may be spaced sufficiently to admit a considerable stream of material between the elements and still operate perfectly in the reduction of the middlings in accordance with my invention. In other words, in using the corrugated elements in a middlings reduction machine,

the process is not one of cutting the middlings; indeed, the reduction of the middlings is not dependent upon all of the grains of the material coming in contact with the ridges.

It is, however, desirable to have means for accurately adjusting the spacing of the elements which operate upon the material-for instance, moving the rolls to and from the In the machine herein illus- 11 having a depending nut 12 ,thatreceives the hollow-threaded member 13 of an adwhich consist of a threaded rod 1 1 and a rod 15 :swi-veled thereto and extending inwardly to asuitableanchorage member 16 at the center of the machine. The member 14 is threaded within the member 13, and the threads for the members 13 and 14 are right and left. handed, so that by turning the hand wheel 17 torotate the hollow-threaded member 13, the latter while. imparting movement to the nut 12 does not 'drive the nut in proportion to the pitch of the thread 13, but in proportion to thediiference between the pitches of the threads 13 and .14, In other words, while uitilizing screw threads of ample strength I develop a movement exceedingly fine and accurate. Another advantage in employing the right and left hand threads arises from the fact that the rod 15 may be held against rotation, and thus made much more substantial and free from lost motion in controlling the pillow block.

In order to throw the rolls away from the concaves, the anchoring connection for the rods 13, 14, and 15 may be in the formof a known construction of eccentric shaft having a controlling handle 18 by which to impart a throw sufficient toopen the rolls at any time when the machine is not in operation.

The rolls have a further adjustment through means of their eccentrics 19 mounted upon the pillow block 11, adapted to be rotated to any desired degree by the op posed set-screws 20 and 21 working against the horns 22. This adjustment is very important in that it permits of the rolls being positioned accurately with relation to the 'con'caves, with the corrugations absolutely parallel. These eccentric adjustments 19 provide a uniform adjustment at both ends, also permit the roll to be raised bodily with relation to the concave, and thus greatly increase the active area of reduction in the passage of the material between the concave and. the roll.

24 represents cleaning brushes which may be of any suitable construction, and which are located directly below the rolls, where they are adjustable through thumb screws- 25 to develop necessary pressure upon the corrugated surfaces of the rolls to insure cleaning the latter, and leaving the rolls in proper condition to act upon the material. In order to insure cleaning of the corrugations, the latter are preferably formed with arcuate bottoms. This, however, is a detail which may be varied if desired.

The process of the present invention is not limited. to the use of a middlings reduction machine in which one of the two members rotates while the other reciprocates. On the contrary, results mightbe realized, at least to a measurably advantageous degree, by having two oppositely reciprocating and coacting members 26, such as suggested schematically in Fig. 9, the members 26 having their opposed and coacting faces corrugated in lines parallel with the direction of feed. Or the process might be carried out to at least a measurable degree by having two oppositely traveling endless steel belts 27 running over supports 28 to hold their acting faces in opposed planes and in coacting relation, said belts being built up of sections so as to adapt them to travel around guide pulleys 29, and being made of metal of such character that it may be provided with corrugations similar to those employed in the roll and concave, 3 and 4, respectively, reduction elements.

Referring to Fig. 7, it is to be noted that the size of the corrugations are shown very much magnified to render the form of the corrugations appreciable. \Vith relation to cylindrical planes of the coacting reducing elements, the sides 30 of the corrugations 30 are at an angle of from 15 to 10. They should not greatly exceed 10 because the angle of incidence between the side of the corrugation and the material against which it strikes would then become so great as to cut or tear the germy or woody fibrous middlings and defeat one of the main purposes of the invention, which is to preserve this portion of the middlings. intact, and to flatten it out .so that it can be readily separated from the flour. .An advantageous pitch to be given to the corrugations of the coacting reducing members is illustrated in Figs. 11 and 12, of which Fig. 11 shows about 1O corrugations to the inch, while Fig. 12 illustrates corrugations numbering about 60 to the inch. In both instances the pitch of the faces which act upon the material, or, in other words, the angle of incidence at which these faces encounter the material to be acted upon, is 25 to the plane of separation between the reducing members.

I claim: v 1. The method of treating middlings, which consists in providing a sheet of such material, subjecting the same to a slow feeding influence continuously in one direction and simultaneously to a reciprocative rubbing movement in a direction transverse to said feeding movement, and thereby causing the particles of such material to rub against one another and release the fine floury substance from the woody fibrous substance.

2. The method of treating middlings, which consists in providing a sheet of such material, subjecting the same to a slow feeding influence continuously in one direction and simultaneously to a reciprocative rubbing movement in a direction transverse to said feeding movement and between faces which extend in the direction of said feed but which are opposed to each other in such transverse direction, and thereby causing the particles of such material to rub against one another and release the fine floury substance from the woody fibrous substance.

3. The method of treating middlings, which consists in providing a sheet of such material, subjecting the same to a slow feeding influence continuously in one direction and simultaneously to a reciprocative rubbing movement in a direction transverse to said feeding movement and between faces which extend in the direction of said feed but which are opposed to each other in such transverse direction, and positioned to impinge against the material at low angles of incidence in such reciprocative rubbing movement, and thereby causing the particles of such material to rub against one another and release the fine floury substance from the woody fibrous substance.

4; The method of treating middlings, which consists in providing a slowly moving sheet of said material, imparting to one side of said sheet of material a continuous movementdownwardly in one direction, and imparting to the opposite side of said sheet of material. a reciprocative agitating movement in a direction transverse to that imparted to the first-named side to cause the particles of said material to rub against each other in various directions and thereby remove the pulverized floury particles from the woody fibrous particles thereof.

5. In a middlings reduction machine,

means for feeding a sheet of middlings, and

a pair of reducing elements spaced apart to 7 receive such sheet between them; said reducing elements having their cooperating faces corrugated in lines parallel to the dlrectlon of feed and having means for developing relative reciprocation between them in a direction transverse to such line of feed; the corrugations of said reducing elements being constructed with faces at low angles to the plane of separation of the rolls and presentin g rubbing faces which encounter the mate-- rial at low angles of incidence.

6. In a middlings reductionmachine, a pair of coacting reducing elements, one of which moves in the direction of feed, and the other of which reciprocates in a direction intersecting said direction of feed; said reducing elements having their cooperating faces corrugated in lines parallel to the direction of feed, and their corrugations being constructed with faces at low angles of incidence to the material upon which they act.

7. In a middlings reduction machine, a pair of coacting reducing elements, one of which moves in the direction offeed, and the other of which reciprocates in a direction intersecting the line of feed; said reducing elements having their coacting surfaces formed with corrugations extending parallel to the line of feed and having their corrugations constructed with faces lying at angles of between 15 and 40 to the plane of separation of the reducing elements.

8. In a middlings reduction machine, a pair of coacting reducing elements, one of which moves in the direction of feed, and the other of which reciprocates in a direction intersecting theline of feed; said reducing elements having their coacting surfaces formed with corrugations extending parallel to the line of feed and having their corrugations constructed with faces lying at an angle of about 25 to the plane of separation of thereducing elements.

Signed at Chicago, in the county of Cook, and State of Illinois this 5th day of March, 1919.

HUGH M. WHITNEY. 

